Generation and characteriztion of regulatory dendritic cells for the amelioration of acute graft versus host disease

Abstract

____________________________________ Nicholas Zavazavaii To my supportive mother, loving husband, and beautiful children vi shared stories about her life and family. She was also like another grandmother to my four children and was fantastic at entertaining them when the occasion arose. A special thanks is extended to Lorraine Tygrett. She started out as my lab Mom when I was an undergraduate and continued to nurture my growth throughout the years. Lorraine became a confidant and close friend. Thanks also go to the many fellow students who have facilitated and often insisted on "helping" me have fun. Emily Hemann and Nicole Chapman have brought fun Sabrina out to play on occasion and I appreciate your persistence and friendship. I also want to thank Alex Boyden for his friendship and constructive feedback. A special thanks also goes to Carla-Maria Alexander and Niki Goldman. You were my closest friends and there for me through the most difficult times in my life. I have missed the two of you dearly. vii ABSTRACT Despite Human Leukocyte Antigen (HLA) matching and use of immunosuppressive drugs, graft-versus-host disease (GVHD) following hematopoietic stem cell transplant (HSCT) is prevalent and often fatal.Additionally, older HSCT recipients experience increased morbidity and mortality. Prophylactic treatment with age-matched syngeneic (recipient strain-derived) cultured regulatory DC (DCreg) has been shown to decrease GVHD-associated mortality in young bone marrow transplanted (BMT) mice.The purpose of this study was to investigate: 1) the potential to generate DCreg from older mice and their subsequent ability to ameliorate GVHD in older BMT mice, 2) the mechanism(s) by which DCreg mitigate GVHD in vivo, 3) the ability of DCreg-treated BMT mice to respond to infectious pathogens, and 4) whether DCreg can be generated under clinically relevant conditions from healthy donor and HSCT recipient PBMCs.To evaluate the efficacy of DCreg treatment in older mice, complete MHC-mismatched BMT mice were treated with DCreg (hereafter referred to as DCreg-treated BMT mice). Although DCreg treatment ameliorated GVHD in older BMT mice, these mice had increased morbidity and decreased survival compared to their young counterparts.Following transfer into BMT mice, older DCreg failed to increase inhibitory molecule (PD-L1 and PIR B) expression while significantly ix (PBMC) cryopreservation, 2) in bovine serum-free media, and 3) from older individuals and HSCT recipients. DCreg were generated from healthy donor and HSCT patient PBMCs isolated from young (<30 years old) and older (> 50 years old) individuals by culturing cells in X-vivo serum-free.